rans s-9

Inverted25

Inverted25

Well-Known Member
Anyone ever flown one of these? Ment a guy the other day who had one and he was talking about how cheap they are to build and operate and how well they fly aerobatics. Turns out you can build one for about 18k. Not bad for how well this guys says they preform. The website says they can compete in sportsman catergory aerobatics.
 
Inverted25 said:
Anyone ever flown one of these? Ment a guy the other day who had one and he was talking about how cheap they are to build and operate and how well they fly aerobatics. Turns out you can build one for about 18k. Not bad for how well this guys says they preform. The website says they can compete in sportsman catergory aerobatics.
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I've heard good things about them. Personally I'd love to build a Skyote - and I think you could get one done that cheap - but they are complex to build. I am also thinking about a Rose Parakeet - easier and also cheap to build.
 
I'm familiar with the Rans company (they're built in Kansas), but I've never seen the S9. I've looked at most of the 2 seat Ran's, but I've never really paid much attention to the single seat models. Just looking around on the internet, looks like the S9, like many other experimental, is probably cheaper to buy a built one than it is to build one. Just know that the engines to power the S9 are the 2 stroke Rotax's, and they do have somewhat of a stigma with them (which is what is unfairly carried over to the 4 stroke models).
 
Inverted25 said:
What is wrong with the two stroke motors?
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There isn't anything wrong with them, its just they have a reputation. They have very, very short TBO times. Like in the 300 hour range, for some of the small Rotax engines. They may or may not be belt driven, depending on the setup. They sound different too (sometimes really loud).

Edit: Don't get me wrong, I'm not saying I wouldn't fly behind one. Just know going in they are different.
 
Wow did some research and see that all 8 engines that rotax makes have a 300 hour tbo. Thats seems kinda ridicolous.
 
Looking around though I see it only cost about 1500 to have them overhauled. Lets do some math here. If you compare that to a normal engine that has a 2000 TBO you would rebuild the 503 6.6 times during that time at a cost of 1500 each time so that would be 10,000. So its still alittle cheaper than running a factory built lycoming. And the intial price is way cheaper. I guess I can see why people use them. I just wouldnt want to be chunking up 1500 bucks every two years which is probally about what it would be to have it overhauled.
 
Inverted25 said:
Looking around though I see it only cost about 1500 to have them overhauled. Lets do some math here. If you compare that to a normal engine that has a 2000 TBO you would rebuild the 503 6.6 times during that time at a cost of 1500 each time so that would be 10,000. So its still alittle cheaper than running a factory built lycoming. And the intial price is way cheaper. I guess I can see why people use them. I just wouldnt want to be chunking up 1500 bucks every two years which is probally about what it would be to have it overhauled.
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Yeah, the 2 stroke Rotax engines don't have much of a TBO. But, they do offer a very high amount of power considering the weight of the engines. Get up into the 4 stroke offerings, and the TBO goes up to 2000 hours for the naturally aspirated version, while the turbocharged version gets I think 1200 or 1400 hours.

Something else to consider, if you start running costs to operate the thing. Its probably going to use MoGas, so that should be somewhat cheaper than AvGas, but you may or may not have ethanol issues, depending on what Rotax says about it.
 
I remember talking to our local mechanic who works on our cherokee 140 about the going away of 100LL. And he said your going to start seeing alot of builders using rotax engines because they were built to handle ethanol in the gas.
 
Inverted25 said:
I remember talking to our local mechanic who works on our cherokee 140 about the going away of 100LL. And he said your going to start seeing alot of builders using rotax engines because they were built to handle ethanol in the gas.
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The engine can handle it, but most of the S-LSA companies don't let the planes use ethanol. Sure the engine can run, but they didn't design the fuel system to deal with it, so they've had issues with fuel lines and tanks falling apart. So, if you wanted to go the Rotax route, build the thing so that the whole fuel system can handle ethanol, not just the engine.

Now only if Rotax would come out with something in the 180 horsepower region. Personally, I think they could do it with a 6 cylinder version of the 912, with a little bit of tuning.
 
What is it about ethanol that is so destructive? If it does that to airplane fuel lines and tanks. Why doesnt it do that to car fuel lines and tanks as well?
 
Inverted25 said:
What is it about ethanol that is so destructive? If it does that to airplane fuel lines and tanks. Why doesnt it do that to car fuel lines and tanks as well?
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It does things to boats too, as they seem to be having the same issues finding non-ethanol gas. Basically, the short story is, the ethanol goes after the fiberglass tanks in a lot of cases. The unprotected fiberglass starts to fall apart, and can cause problems throughout the system. Also, ethanol absorbs the water, so if you get some in the system, its all going to go through at the same time, not really something you want to have happen.

It is my understanding that you can get protective coatings for fiberglass tanks, in order to make them handle the ethanol. Not sure how common it is yet, but I'd imagine they'll get more common as we see less and less ethanol free MoGas
 
What airplanes use fiberglass tanks? I'm pretty sure when we pulled the skins on the wings of the cherokee last year to replace fuel lines the tanks looked like either stainless steel or aluminum.
 
Inverted25 said:
What airplanes use fiberglass tanks? I'm pretty sure when we pulled the skins on the wings of the cherokee last year to replace fuel lines the tanks looked like either stainless steel or aluminum.
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The ones that use Rotax engines. Many of them are weight limited, so by going the composite/fiberglass route, they save some weight. Lots of the LSA's have them, as far as I know.

For instance, a non tank related problem with ethanol in the CTSW (my avatar), is they have trouble with the fuel filter. In order to run ethanol (up to 10%) MoGas, you have to change filters. The biggest issue is water. Ethanol picks up the water, so if you let the plane sit for a long time with ethanol MoGas, expect to sump.
 
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